1. Field of the Invention.
This invention pertains to digital timer fuzes (DTF) and systems associated therewith.
2. Description of the Prior Art.
Time fuzes are widely used in Navy weapons principally because they are less costly than proximity fuzes. This advantage, however, is offset by a compromise in weapon performance, since fuze function time is a tradeoff based on the statistical average of typical weapon deployments. Also, when launching air-to-surface weapons, the pilot is constrained to a specific weapon delivery flight envelope to maintain weapon effectiveness. As a result of such repeated trajectories, the launch aircraft is more vulnerable to hostile action.
Because it is settable, the proposed DTF system can be used in place of conventional fixed-timer fuzes to provide improved weapon performance with an enlarged launch envelope. This system would also permit the use of low-cost time fuzing in some applications that previously required higher-cost active or proximity fuzing. For example, the DTF could replace costly autonomous slant-range fuzes, which function at ranges from several hundred feet to over 1,000 feet. In such instances, a cost saving in expended fuze hardware of approximately 30 to 1 could be realized.
The advanced capabilities of high accuracy (approximately 0.1%) and almost instantaneous settability (a few milliseconds) offered by the DTF open many new military applications for a timer of this type. However, only the air-to-surface weapon application will be addressed here. By replacing fixed-delay timers, the DTF can greatly enlarge the launch envelope of such weapons. In addition to providing the pilot with greater flexibility in his weapon delivery tactics, weapon effectiveness can be maximized for each launch. This can be accomplished by accurately determining the optimum warhead function time for each weapon to be launched, and by setting each fuze accordingly the instant before launch. Such a procedure involves (1) acquisition of geometric and kinematic data to define the weapon trajectory after launch,(2) manipulation of this data to obtain the optimum fuze delay time for the weapon to be launched, and (3) setting the fuze delay time before launch.